.header {
    position: fixed;
    left: 0;
    top: 0;
    width: 100%;
    height: 56px;
    padding: 0;
    background: #673ab7;
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.5);
    z-index: 50;
}

.header .inner {
    max-width: 1080px;
    margin: 0 auto;
    display: flex;
    overflow: hidden;
}

.header h1 {
    float: left;
    margin: 0;
    padding: 0 15px;
    font-size: 24px;
    line-height: 56px;
    font-weight: 400;
    color: #fff;
}

.header nav {
    font-size: 100%;
    margin-left: auto;
}

.header nav a {
    display: inline-block;
    height: 56px;
    line-height: 56px;
    padding: 0 15px;
    min-width: 50px;
    text-align: center;
    background: rgba(255, 255, 255, 0);
    text-decoration: none;
    color: #fff;
    will-change: background-color;
}

.header nav a:hover,
.header nav a:active {
    background: rgba(0, 0, 0, 0.2);
}

.header nav a.active {
    background: rgba(0, 0, 0, 0.4);
}
